package com.jgk.gwt.recipes.stockwatcher.client;

import java.util.ArrayList;
import java.util.Date;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.i18n.client.DateTimeFormat;
import com.google.gwt.i18n.client.NumberFormat;
import com.google.gwt.user.client.Random;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;

/**
 * Entry point classes define <code>onModuleLoad()</code>.
 */
public class JgkStockWatcher implements EntryPoint {
	/**
	 * The message displayed to the user when the server cannot be reached or
	 * returns an error.
	 */
	private static final String SERVER_ERROR = "An error occurred while "
			+ "attempting to contact the server. Please check your network "
			+ "connection and try again.";

	private static final int REFRESH_INTERVAL = 5000; // ms

	/**
	 * Create a remote service proxy to talk to the server-side Greeting
	 * service.
	 */
	// private final GreetingServiceAsync greetingService = GWT
	// .create(GreetingService.class);

	private VerticalPanel mainPanel = new VerticalPanel();
	private FlexTable stocksFlexTable = new FlexTable();
	private HorizontalPanel addPanel = new HorizontalPanel();
	private TextBox newSymbolTextBox = new TextBox();
	private Button addStockButton = new Button("Add");
	private Label lastUpdatedLabel = new Label();
	private ArrayList<String> stocks = new ArrayList<String>();
	private StockPriceServiceAsync stockPriceSvc = GWT
			.create(StockPriceService.class);
	private Label errorMsgLabel = new Label();
	private Label helpMsgLabel = new HTML("ERR will cause error...then remove ERR to clear error.<br/>youw");

	public void onModuleLoad() {

		// TODO Create table for stock data.
		stocksFlexTable.setCellPadding(6);
		stocksFlexTable.setText(0, 0, "Symbol");
		stocksFlexTable.setText(0, 1, "Price");
		stocksFlexTable.setText(0, 2, "Change");
		stocksFlexTable.setText(0, 3, "Remove");

		// Add styles to elements in the stock list table.
		stocksFlexTable.getRowFormatter().addStyleName(0, "watchListHeader");
		stocksFlexTable.addStyleName("watchList");
		stocksFlexTable.getCellFormatter().addStyleName(0, 1,
				"watchListNumericColumn");
		stocksFlexTable.getCellFormatter().addStyleName(0, 2,
				"watchListNumericColumn");
		stocksFlexTable.getCellFormatter().addStyleName(0, 3,
				"watchListRemoveColumn");

		// TODO Assemble Add Stock panel.
		addPanel.add(newSymbolTextBox);
		addPanel.add(addStockButton);
		addPanel.addStyleName("addPanel");
		addStockButton.addClickHandler(new ClickHandler() {

			@Override
			public void onClick(ClickEvent event) {
				addStock();

			}
		});

		// Listen for keyboard events in the input box.
		newSymbolTextBox.addKeyPressHandler(new KeyPressHandler() {
			public void onKeyPress(KeyPressEvent event) {
				if (event.getCharCode() == KeyCodes.KEY_ENTER) {
					addStock();
				}
			}

		});

		// TODO Assemble Main panel.
	    errorMsgLabel.setStyleName("errorMessage");
	    errorMsgLabel.setVisible(false);
	    mainPanel.add(helpMsgLabel);
	    mainPanel.add(errorMsgLabel);		
		mainPanel.add(stocksFlexTable);
		mainPanel.add(addPanel);
		mainPanel.add(lastUpdatedLabel);

		// TODO Associate the Main panel with the HTML host page.
		RootPanel.get("stockList").add(mainPanel);

		// TODO Move cursor focus to the input box.
		newSymbolTextBox.setFocus(true);

		// Setup timer to refresh list automatically.
		Timer refreshTimer = new Timer() {
			@Override
			public void run() {
				refreshWatchList();
			}

		};
		refreshTimer.scheduleRepeating(REFRESH_INTERVAL);

	}

	/**
	 * Add stock to FlexTable. Executed when the user clicks the addStockButton
	 * or presses enter in the newSymbolTextBox.
	 */
	private void addStock() {
		// Window.alert("add a stock...");
		final String symbol = newSymbolTextBox.getText().toUpperCase().trim();
		newSymbolTextBox.setFocus(true);

		// Stock code must be between 1 and 10 chars that are numbers, letters,
		// or dots.
		if (!symbol.matches("^[0-9A-Z\\.]{1,10}$")) {
			Window.alert("'" + symbol + "' is not a valid symbol.");
			newSymbolTextBox.selectAll();
			return;
		}

		newSymbolTextBox.setText("");

		// TODO Don't add the stock if it's already in the table.
		if (stocks.contains(symbol))
			return;
		// TODO Add the stock to the table.
		int row = stocksFlexTable.getRowCount();
		stocks.add(symbol);
		stocksFlexTable.setText(row, 0, symbol);
		stocksFlexTable.setWidget(row, 2, new Label());
		// TODO Add a button to remove this stock from the table.
		Button removeStockButton = new Button("xMF");
		removeStockButton.addStyleDependentName("remove");
		removeStockButton.addClickHandler(new ClickHandler() {
			public void onClick(ClickEvent event) {
				int removedIndex = stocks.indexOf(symbol);
				stocks.remove(removedIndex);
				stocksFlexTable.removeRow(removedIndex + 1);
			}
		});
		stocksFlexTable.setWidget(row, 3, removeStockButton);
		// TODO Get the stock price.
		refreshWatchList();

	}

	private void refreshWatchList() {
		// Initialize the service proxy.
		if (stockPriceSvc == null) {
			stockPriceSvc = GWT.create(StockPriceService.class);
		}

		// Set up the callback object.
		AsyncCallback<StockPrice[]> callback = new AsyncCallback<StockPrice[]>() {
			public void onFailure(Throwable caught) {
				// TODO: Do something with errors.
				//Window.alert("OUCH...onFailure");
				// If the stock code is in the list of delisted codes, display an error message.
		        String details = caught.getMessage();
		        if (caught instanceof DelistedException) {
		          details = "Company '" + ((DelistedException)caught).getSymbol() + "' was delisted";
		        }

		        errorMsgLabel.setText("Error: " + details);
		        errorMsgLabel.setVisible(true);				
			}

			public void onSuccess(StockPrice[] result) {
				updateTable(result);
			}
		};

		// Make the call to the stock price service.
		stockPriceSvc.getPrices(stocks.toArray(new String[0]), callback);
	}

	/**
	 * Generate random stock prices.
	 */
	private void refreshWatchListOld() {
		final double MAX_PRICE = 100.0; // $100.00
		final double MAX_PRICE_CHANGE = 0.02; // +/- 2%

		StockPrice[] prices = new StockPrice[stocks.size()];
		for (int i = 0; i < stocks.size(); i++) {
			double price = Random.nextDouble() * MAX_PRICE;
			double change = price * MAX_PRICE_CHANGE
					* (Random.nextDouble() * 2.0 - 1.0);

			prices[i] = new StockPrice(stocks.get(i), price, change);
		}

		updateTable(prices);
	}

	/**
	 * Update the Price and Change fields all the rows in the stock table.
	 * 
	 * @param prices
	 *            Stock data for all rows.
	 */
	private void updateTable(StockPrice[] prices) {
		for (int i = 0; i < prices.length; i++) {
			updateTable(prices[i]);
		}
		// Display timestamp showing last refresh.
		lastUpdatedLabel.setText("Last update : "
				+ DateTimeFormat.getMediumDateTimeFormat().format(new Date()));
		
		// Clear any errors.
	    errorMsgLabel.setVisible(false);		

	}

	/**
	 * Update a single row in the stock table.
	 * 
	 * @param price
	 *            Stock data for a single row.
	 */
	private void updateTable(StockPrice price) {
		// Make sure the stock is still in the stock table.
		if (!stocks.contains(price.getSymbol())) {
			return;
		}

		int row = stocks.indexOf(price.getSymbol()) + 1;

		// Format the data in the Price and Change fields.
		String priceText = NumberFormat.getFormat("#,##0.00").format(
				price.getPrice());
		NumberFormat changeFormat = NumberFormat
				.getFormat("+#,##0.00;-#,##0.00");
		String changeText = changeFormat.format(price.getChange());
		String changePercentText = changeFormat
				.format(price.getChangePercent());

		// Populate the Price and Change fields with new data.
		stocksFlexTable.setText(row, 1, priceText);
		Label changeWidget = (Label) stocksFlexTable.getWidget(row, 2);
		changeWidget.setText(changeText + " (" + changePercentText + "%)");
		// stocksFlexTable.setText(row, 2, changeText + " (" + changePercentText
		// + "%)");

		// Change the color of text in the Change field based on its value.
		String changeStyleName = "noChange";
		if (price.getChangePercent() < -0.1f) {
			changeStyleName = "negativeChange";
		} else if (price.getChangePercent() > 0.1f) {
			changeStyleName = "positiveChange";
		}

		changeWidget.setStyleName(changeStyleName);
	}
}
